Bitumen recovery from oil sands presents technical and economic challenges due to high viscosity of the bitumen at reservoir conditions. Thermal recovery processes such as steam assisted gravity drainage (SAGD) inject steam to heat the bitumen. The bitumen with reduced viscosity due to this heating then drains and is recovered.
One approach to facilitate the recovery utilizes flow control devices (FCDs), which are tools that regulate fluids passing into or out of wellbores by choking flow. The FCDs provide benefits with respect to steam conformance along the wellbores, cumulative production, steam-to-oil ratios and limiting steam production. Successful designing of completions employing the FCDs relies on understanding how the FCDs influence what happens in reservoirs.
However, prior reservoir simulators fail to account for behavior of the FCDs under operating conditions. Traditional tools to estimate ΔP assume it is a function of Reynold's number (Re, which impounds Flow rate, Viscosity and Density). Reservoir simulators rely on this assumption in their computations. This assumption does not hold when there are phase transitions in the fluids (as determined by lab tests conducted under these conditions). Flashing of the water within fluids passing through the FCDs further complicates describing performance of the FCDs. As a result, existing techniques lack ability to provide desired simulations when utilizing the FCDs in these thermal recovery processes.
Current models are inadequate to simulate the behavior of the standard FCDs under SAGD conditions. The current state of the art is thwarted by the lack of data on how FCDs behave at SAGD conditions. Using current techniques, each FCD is simulated as a separate wellbore and then impose constraints on bottom hole pressures, rates and steam-trap control. The behavior of the FCD is then forced in to the simulation by changing the well constraints. In the producer well the live steam entry is limited. In the injector well the bottom hole pressure and steam injection rate are limited.
Therefore, a need exists for methods and systems for reservoir simulation including applications with FCDs utilized in the thermal recovery processes. The gathering of laboratory data to characterize FCDs under SAGD representative conditions and a reservoir simulator capable of addressing the behavior of FCDs.